While the invention may be used for other purposes, it provides particular advantages when used in blast furnaces, and therefore will be described as so used.
To achieve greater production and increased efficiencies and economies of blast furnace construction and operation, recent blast furnace designs have tended toward large furnaces of substantially higher internal top pressures of gas than have heretofore been common. In new furnaces being designed or built, top pressures range as high as 40 pounds per square inch gage (psig), hearth diameters range up to fifty feet or more, and diameters at the stockline vicinity range up to thirty feet or more, while iron productions range up to ten thousand tons per day.
These factors of high gas pressure, large furnace size, and large productions have imposed severe problems in the design and operation of the charging apparatus for such furnaces to permit charging of the large quantities of charge materials in the desired distribution over the large internal cross sectional area of such furnace, to prevent during and between charging leakage from the furnace of the gas at such high pressures, and to prevent fluidization of the charge material within the furnace due to irregularities in the stockline that can cause localized channeling through the mass of charge material in the furnace and improper furnace operation.